Charge enough
To stay in business.
That you’re not competing on price.
To be profitable.
That you can take time off.
To be picky about the projects you take on.
That you can survive late payments.
To give good service.
That you don’t resent the work after ten minutes.
To cover your expenses.
That projects aren’t a race against the clock.
To accommodate small scope changes.
That you can pay for help when you need it.
To start a pension.
That clients respect you.
To build a buffer.
That you can take holidays.
To cover the instability of work.
That you don't need to juggle too many projects.
To stay in business.